<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
    .parent {
        width: 600px;
        height: 200px;
        border: 1px solid red;
        display: table;
    }
    .child {
        display: table-cell;
        vertical-align: middle;
    }

    </style>
</head>
<body>
    <div class="parent">111
        <div class="child">111</div>
    </div>
</body>
</html>